The Leigh Light

[Hobilar]

Finding a U-Boat at night in the Bay of Biscay was not exactly the easiest of tasks for the aircrew of Coastal Command. The U-Boats had to surface after dark in order to recharge their batterys, but even Radar equipped aircraft, although they could often detect the surfaced submarine, found it difficult to actually spot the small craft so that they could make an attack.

The solution was to fit a powerful searchlight under the aircraft which could illuminate the target and thus make bomb aiming more accurate. The special searchlight was conceived, designed and built by Squadron Leader Humphrey de Verde Leigh, and so became universally known as the Leigh Light.

After testing in 1941 No. 172 Squadron equipped with Leigh Light Wellington Bombers in the spring of 1942, and made their first attack on an Axis submarine on the 3 June 1942 when the Italian submarine Luigi Torelli was attacked and damaged forcing it to return to port for repairs. A month later the first kill was achieved when U502 was attacked and sent to the bottom. Over the following weeks eleven more U-Boats were sighted, six being attacked, sinking one and damaging two more.

The use of Leigh lights had an effect on German tactics. By mid July the U-Boats had taken to surfacing by day making the RAF's task much easier. Over the next four months the number of sightings rose from 14 in June, to 16 in July, 34 in August, and 37 in September, resulting in four submarines sunk and eight damaged.

From October however the number of U-Boat sightings began to decrease again as the German Navy began fitting a device known as Metox to their submarines which could detect Radar emissions.